Tethered mine hunting system

ABSTRACT

A tethered mine hunting system capable of aerial deployment comprises a lift module attached to an aircraft support vehicle by primary tether and a submarine vehicle attached to said lift module by secondary tether. The lift module and submarine vehicle are configured so as to permit the submarine vehicle to be garaged within the lift module during launch and recovery of the system. A source of hydraulic motive power is located within the lift module and is attached to the submarine vehicle via the secondary tether so as to permit the submarine vehicle to have very low acoustic and magnetic signatures. Additionally, the lift module contains other support equipment and electroacoustic transducers.

United States Patent 1 1 1111 3,880,103

Talkington Apr. 29, 1975 [54] TETHERED MINE HUNTING SYSTEM 3 719,l 163/1973 Burton et a1. 114/16 R X [75] Inventor: Howard R. Talkington, LaJolla,

Calif- PllI7l(ll E.\'aminerSamue1 Femberg Attorney, Agent, orFirmRichard S. Sciascia; Ervin [73] Assignee: The United States ofAmerica as F. J h n; William T skfier represented by the Secretary ofthe Navy, Washington. DC. [57] ABSTRACT [22] Fled: 1972 A tethered minehunting system capable of aerial de- 21 App| 2 3 127 ployment comprisesa lift module attached to an aircraft support vehicle by primary tetherand a submarine vehicle attached to said lift module by secondary U.S. ut i R t th Th d submarine hi l are [51] hit. Cl. B63g 8/00 figured so asto permit the Submarine Vehicle to be [58] held of Seal-chm 114/16 240R3 raged within the lift module during launch and recov- 61/69 R169 A;37/54 56 ery of the system. A source of hydraulic motive power islocated within the lift module and is attached to the [56] ReferencesC'ted submarine vehicle via the secondary tether so as to UNITED STATESPATENTS permit the submarine vehicle to have very low acous- 3105453 109 3 Hayes 1 9 R X tic and magnetic signatures. Additionally, the liftmod- 3.38l.485 5/1968 Crooks et a1... 61/69 R ule contains other supportequipment and electro- 3 550386 12/1970 Ballingcr l l l. 114/16 R Xacoustic transducers.

3.618.236 11/1971 Pipkin l l l l 37/63 3.626.703 12/1971 Richburg 114/1610 Claim- 2 Drawing Figures PATENTEDAPRZSISYS 1880,1013

SHEET 10F 2 FlG.l

TETHERED MINE HUNTING SYSTEM STATEMENT OF GOVERNMENT INTEREST Theinvention described herein may be manufac' tured and used by or for theGovernment of the United States of America for governmental purposeswithout the payment of any royalties thereon or therefor.

FIELD OF THE INVENTION This invention pertains to the fields of navalarchitecture and marine engineering. More particularly, the inventionpertains to the field of remotely controlled submarine vehicles. Ingreater particularity, the invention pertains to remotely controlledsubmarine vehicles operating from a tethered control arrangement. Instill greater particularity, the invention pertains to a tetheredsubmarine vehicle having a lift module attached to the support vehicleby means of a primary tether and a submarine vehicle operating from, andattached to, the lift module by means of a secondary tether.

DESCRIPTION OF THE PRIOR ART In many marine activities, it is necessaryto identify and recover, or perform work on, objects which are locatedbeneath the surface of the sea. For example, the fields of archeology,geology, petroleum production, and transcontinental communications havetaken men into the submarine environments which heretofore have beenlittle known outside the field of submarine warfare. In all of thesefields of endeavor, an object is located by means of conventionaldetection and ranging equipment from the surface of the water and diversare sent down to perform the necessary inspection or work upon theobject located. Quite obviously, such operations are greatly influencedby the weather conditions and water condition which will permit theemployment of divers. Experience has shown that such conditions as wouldpermit the optimum use of divers occur only approximately half of thetime even in temperate climate zones.

It has been proposed in the prior art to use small submersible vehiclesto replace the diver in such opera tions. However, such submarinevehicles are expensive to operate and still require considerable surfacesupport in launch and recovery thereof. Too, in mine hunting operationssuch vehicles ofttimes actuate the detonating mechanism on the marinemine as the submarine vehicle approaches the mine.

Another shortcoming of the prior art systems for locating underwaterobjects has been the necessity of keeping a relatively large-sizesurface ship deployed for extended periods of time. Because of the crewrequirements for such vessels and their large fixed operating costscombined with their relatively slow speed, the cost of such operationsbecomes prohibitive. Ifa rotary winged aircraft or lighter than airaircraft could be employed in such operations, the cost and time couldbe greatly improved. However, heretofore submersible vehicles capable ofremote operation have not been able to withstand launch and recoveryfrom a support vehicle above the surface of the water.

SUMMARY OF THE INVENTION The system of the invention uses a low noise,low magnetic signature, submarine vehicle operating from a tether. Thesubmarine vehicless tether is attached to a lift module. The liftmodule, in turn, contains a garage space for the submarine vehicle, asource of motive power for the submarine vehicle and its attachments,and auxiliary ranging and electroacoustic equipment. The lift module isconnected to a suitable aircraft support vehicle located above thesurface of the water by means of another tether arrangement.

STATEMENT OF THE OBJECTS OF THE INVENTION It is, accordingly, an objectof this invention to provide an improved tethered vehicle system.

Another object of this invention is to provide a tethered vehicle systemfor submarine exploration and investigation from an aircraft supportvehicle.

Another object of the present invention is to provide a tetheredsubmarine vehicle mine hunting system.

A still further object of the present invention is to provide a tetheredsubmarine mine hunting system employing a separate submarine minehunting vehicle and a lift module.

Another object of this invention is to provide a submersible vehicleoperating from a tether which has minimal electromagnetic and acousticsignature.

Still another object of the present invention is to provide a tetheredmine hunting system employing a lift hydraulically powered submarinevehicle operating from a tethered lift module.

Yet another object of the present invention is to provide a tetheredvehicle mine hunting system employing a lift module containing apropulsive power source for the tethered vehicle.

Still another object of the present invention is to provide a tetheredmine hunting system operating from a lift module which containselectroacoustic search transducers.

Still another object of the present invention is to provide a tetheredmine hunting system employing a hydraulically powered submarine vehicleoperating from a tether to a suitable support and lift module which, inturn, is tethered to an aerial support vehicle.

These and other objects of the invention will become more readilyapparent from the ensuing specification when taken with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view showingthe system according to the invention being used in a mine huntingsituation; and

FIG. 2 is a schematic representation of the various componentscomprising the system of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, anarrangement of the system of the invention to be used in a mine huntingenvironment will be described. It should be noted that although thesystem of the invention will be described in connection with itsapplication to the mine hunting problem, other applications where thesystem of the invention may be used will readily suggest themselves. Asupport vehicle, such as rotarywinged aircraft 11, having sufficientpower and space requirements for operating personnel is shown deployedabove the surface of the water. A lift module 12 is illustrated as beingconnected to rotary wing aircraft 11 by means of a suitable primarytether l3.

A submarine vehicle 14 is attached to lift module 12 by means of asecondary tether 15. As illustrated.-submarine vehicle 14 has atelevision camera 16 mounted in its forward portion to photograph and totransmit images back to the support vehicle by means of tethers 15 and13. Further, in waters where sufficient natural illumination is notpresent the object being photographed by television camera 16 may beilluminated by suitable light sources 17 which are also attached to theforward portion of submarine vehicle 14 and directed in front thereof.No particular details are shown for TV camera 16 or light source 17 asthey may be conventional prior art arrangements. For example, TV camera16 may be of the type manufactured by Hydro Products under thedesignation Model 125." Light sources 17 may be electrically powered bymains carried in tethers 13 and 15 or battery powered. In some instanceswhere even further reduction in magnetic signature is required the lightsources 17 may be photochemically operated.

A suitable manipulator arm 18 is attached to submarine vehicle 14 forperforming work and investigative assignments upon objects in the nearvicinity of submarine vehicle 14. Like TV camera 16, any suitable priorart manipulator may be used in this environment in dependence upon theparticular work assignments encountered. However, for purposes ofillustrative completeness, it should be noted that the manipulator armdescribed in U.S. Pat. No. 3,703,968 for Linear Linkage Manipulator Armby Richard W. Uhrich et al., issued on Nov. 28, 1972, has provensatisfactory.

It will be observed that submarine vehicle 14 has motor 19 mounted oneither side thereof and a buoyancy chamber, designated at 20, on theinterior thereof to regulate propulsive movments and depths about liftmodule 12. Although some latitude is permitted in choosing motors l9 andbuoyancy chamber 20 from designs of the prior art for the provision ofpropulsive force and buoyancy for submarine vehicle 14, it is highlydesirable that such systems exhibit very low acoustic and magneticsignature properties. For this reason, the buoyancy chamber 20 and motor19 are preferably of the hydraulic control type such as that disclosedin U.S. Pat. No. 3,780,220 by Bruce R. Fugitt et al., for Remote ControlUnderwater Observation Vehicle" issued on Dec. 18, 1973.

If desired, submarine vehicle 14 may carry additional auxiliaryequipment as indicated generally at 21. Such auxiliary equipment mayinclude, for example, an explosive charge for providing neutralizationof marine mines or a sonar reflector having identifiable conductioncharacteristics for marking objects examined underwater to aid in theirrelocation. Also, although only a single auxiliary equipment package 21is illustrated, a plurality of such packages may be carried by submarinevehicle 14, if desired. Likewise, a variety of methods of release of thepackage are possible. For example, the package may be extracted bymanipulator 18, released by a catch mechanism and allowed to drop, orejected. For purposes of completeness, the invention may be consideredas using the package shown and described in U.S. Pat. No. 3,757,633issued on Sept. 11, 1973 for Visual Marker System to Paul K. Salzman etal.

A suitable tool 22 is shown carried on the distal end of manipulator 18for performing the desired work or investigative action upon objects inthe vicinity of submarine vehicle 14. Such a tool may be, for example,an

explosive type cable cutter to sever anchoring cables,

for marine mines or other chains or cables attached to the objects underinvestigation. Of course, if desired, tool 22 may be a gripping,hand-like device to move or operate underwater equipment. A variety ofsuch engaging hands are known in the prior art and choice between themis a matter of design within the purview of one skilled in the art.

From the foregoing description it may be seen that submarine vehicle 14may be hydraulically operated and that tether 15 need carry only smallelectrical currents necessary to operate TV camera 16 and lights 17.Because of the length of cable 13, it is desirable that the hydraulicpower source for manipulator 18, motors l9, buoyancy chamber 20, andoperational releases for auxiliary package 21 be provided from liftmodule 12 rather than from support vehicle 11. Further, to prevententanglement of tether 15, it is desirable that suitable retractablestorage be provided for tether 15 within lift module 12. These functionsare provided by means of a suitable winch mechanism 25 and a hydraulicpower source 26 carried within lift module 12. The control of theparticular functions is provided by means of a conventional solenoidoperated hydraulic valve arrangement indicated generally at 27. Suchhydrualic power sources and valve arrangements are common in the priorart and unnecessary for the understanding of the invention and thereforeare not described in greater detail It will be observed that lift module12 is enclosed on one end but has provision for submarine vehicle 14 toenter the other end thereof and to be garaged within its hull. Thisarrangement protects submarine vehicle 14 and its associated equipmentfrom damage as lift module 12 passes through the air-water interfaceduring launch and recovery from support vehicle 11.

As shown, an electroacoustic transducer 23 is mounted on lift module 12and may be connected, via tether 13, to a conventional search sonarlocated within the support vehicle. Again, sonar systems of the typeemploying a remote transducer are common in the prior art and a choiceamong them may be made by one versed in the electroacoustic arts independence upon the particular design parameters required.

It will also be noted that a second electroacoustic transducer,indicated at 24, is mounted on lift module 12 and may be connected, viatether 13, to other acoustic signal sources for providing the desiredacoustic signals within the water. For example, such acoustic signalsmay provide an influence sweep for marine mines or, optionally, acompressional wave communication system for submarine vehicles operatingin the vicinity. Likewise, such a communication system may establish acommunication link between a plurality of support vehicles 11 withoutresort to electromagnetic communications, an obvious advantage in somenaval operations.

Referring to FIG. 2, the manner in which the various componentscomprising the system interface with one another will now be described.The major portions of the system such as support vehicle 11, lift module12, and submarine vehicle 14 are indicated by broken line boxes. Thevarious interconnecting lines represent the connections made via tethers13 and 15.

As shown, a source of electrical power 31 is located within aircraft 11and may, if desired, comprise a portion of the aircrafts electricalsystem. The sonar control system 32 is also located within aircraft l1and is connected by suitable electrical connections to the sonartransducer 23 in lift module 12. Likewise, acoustic signal source 33 issimilarly connected to auxiliary electroacoustic transducer 24.Acoustical signal source 33 may be any conventional source of electricalanalog signals to produce a desired acoustic energy from transducer 24.For example, acoustical signal source 33 may produce an electricalanalog of acoustic signatures to provide a countermeasure sweep formarine mines or, conversely, acoustic signal source 33 may be theelectronic portion of a conventional compressional wave acousticcommunication system.

The next component part of the system of the invention indicated asbeinghoused within support vehicle 11 is the function control mechanism34. This function control mechanism comprises an electrical switchingand control arrangement having a plurality of switching mechanisms eachcorresponding to a desired operational function of submarine vehicle 14.Such operational functions include the direction and magnitude ofpropelling force supplied by motors 19, the operation of ballast chamber20, and the operation of manipulator arm 18. A wide variety of suchinput switching devices is known in the prior art and choice betweenthem is within the purview of one skilled in the art in dependence uponthe particular function being controlled. Since such switches are wellknown and conventional, further description thereof is not deemedwarranted.

A winch 35 is also located within support vehicle 11 and has tether line13 wound thereon. Of course, tether line 13 contains a tension bearingmember, indicated in FlG. 2 by a heavy broken line, connecting winch 35with lift module 12. The method of attachment of this tension member tothe submarine vehicle is likewise conventional and therefore need not bedescribed in detail for the understanding of the invention.

A video readout 36 is also located within support vehicle 11 and isconnected to TV camera 16 through internal connections made within liftmodule 12 so as to provide a visual indication of the object field beingphotographed by television camera 16.

As previously noted, lift module 12, in addition to housing submarinevehicle 14, houses sonar transducer 23 and auxiliary transducer 24. Asindicated above, these transducers are connected to their appropriatesignal sources within support vehicle 11 by means of electricalconnections contained in tether line 13. A winch 25 is also containedwithin lift module 12. As indicated in FIG. 2, winch 25 may beconveniently powered by a hydraulic motor operating from a commonhydraulic power source 26. The operation of winch 25 as well as thevarious hydraulically controlled functions on submarine vehicle 14 iscontrolled by means of valve mechanism 27.

Valve mechanism 27 is an assembly of a plurality of electricallyoperated fluid valves which control the individual hydraulicallyoperated mechanisms on lift module 12 and submarine vehicle 14. The useof hydraulic control in these applications provides submarine vehicle 12with a reduced electrical and magnetic signature thereby permitting itto closely approach influence type mines.

As shown by FIG. 2, the previously described systems contained onsubmarine vehicle 14, TV-camera 16, lights 17, manipulator 18,propulsion motors l9, buoy- 'ancy chamber 20, and auxiliary equipment 21are all connected to their respective sources of power within liftmodule 12 by a tether 15. Tether 15 is made neutrally buoyant byconventional underwater cabling techniques so as to offer a minimum ofresistance and drag to submarine vehicle 14 as it moves about liftmodule 12.

While the foregoing description will enable one versed in the marineengineering and oceanographic instrumentation arts to make and use theinvention, the invention will be better understood with reference to thefollowing preferred mode of operation.

Preferred Mode Of Operation Of course, the operation of the presentsystem of the invention begins with the submarine vehicle 14 within liftmodule 12 and supported on support vehicle 11. As previously described,support vehicle 11 may be any suitable vehicle which may be rapidlydeployed to an area and operate at relatively low speeds above thesurface thereof. Rotary wing aircraft, lighter than air aircraft, andcertain surface effect vehicles are completed and have provensatisfactory in the operation of the system of the invention. When thevehicle 11 is in the operational area, winch 35 is operated to lowerlift module 12 into the water by means of tether 13. Support vehicle 11then moves lift module 12 about the area in which search andsurveillance is being conducted while operating the sonar systemincluding sonar console 32 and sonar transducer 23. When an object to beinvestigated has been encountered, support vehicle 11 maneuvers liftmodule 12 within a convenient operational range and submarine vehicle 14is caused to disengage and maneuver from lift module 12.

During this operation, of course, winch 25 is operated so as to pay outtether 15 and permit submarine vehicle 14 to approach the desiredobject.

Referring to FIG. 1, a marine mine indicated at 41, supported on ananchor chain 42 from an anchor 43 resting on the bottom, is beinginvestigated by submarine vehicle 14. Vehicle 14 may approach mine 41and by means of manipulator arm 18 cause a suitable cutting tool 22 toengage and sever anchor chain 42 thereby separating buoyant mine 41 fromanchor 43. Mine 41 when it reaches the surface may be detonated by asmall arms fire or, alternatively, disarmed and picked up by the surfacevehicle.

Alternatively, the position of mine 41 may be marked by suitableauxiliary equipment 21 comprising a sonar reflector or an acousticmarker generator called a pinger. Also, auxiliary equipment 21 mayinclude an explosive charge which may be placed adjacent a mine of thenonmoored or nonbuoyant type. In such instances, explosive charge 21 maybe detonated by a suitable timing mechanism.

Of course, other means of mine countermeasures may be employed if mine41 is of the acoustically detonated type. For example, an acousticsignal may be generated by electroacoustic transducer 24 in response tosignals supplied by acoustic signal source 33 to detonate the mine assubmarine vehicle 14 permits the mine counter-measures operator toobserve the effect of the various acoustic signals on the mine. When themine neutralization or investigation operation has been completed,submarine vehicle 14 may be guided back to lift module 12 by means ofpropulsion motors 19 and winch 25 retracting tether line 15. Whensubmarine vehicle 14 is garaged within lift module 12, winch 35 withinsupport vehicle 11 is operated so as to recover lift module 12 withsubmarine vehicle 14 inside.

While the foregoing description of the invention per tains to minecountermeasures. it will be readily apparent that other useful workprojects may be performed by the system of the invention. Such fields ofutilization include marine salvage, underwater geology and archeology,and petroleum exploration for example.

The foregoing description taken together with the appended claimsconstitutes a disclosure such as to enable a person skilled in themarine engineering and naval architecture arts and having the benefit ofthe teachings contained therein to make and use the invention. Further.the structure herein described meets the objects of invention. andgenerally constitutes a meritorious advance in the art unobvious to sucha skilled worker not having the benefit of the teachings containedherein.

Obviously, many modifications and variations of the present inventionare possible in the light of the above teachings, and. it is thereforeunderstood that within the scope of the disclosed inventive concept, theinvention may be practiced otherwise than specifically described.

What is claimed is:

I. An undersea tethered vehicle system comprising:

a support vehicle;

a primary tether connected to said support vehicle and extendingdownwardly therefrom for conducting electrical currents and supportingtensional forces therealong;

a lift module attached to the primary tether for support thereby;

a submarine vehicle configured for retention within the lift module;

a source of motive power housed within the lift module; and

a secondary tether connected between the submarine vehicle and the liftmodule and effectively connected to said source of motive power withinthe lift module for transmission of the motive power therealong andeffectively connected to the primary tether for transmission ofelectrical currents therealong to permit the submarine vehicle'smovement into and out of the lift module and within a predeterminedrange thereabout.

2. A tethered vehicle system according to claim 1 wherein the supportvehicle is an aircraft.

3. A tethered vehicle system according to claim 1 wherein the liftmodule is enclosed on one end to minimize hydrodynamic interactionbetween the retained submarine vehicle and the water during launch andrecovery of the system.

4. A tethered vehicle system according to claim 1 further including awinch housed within the lift module and effectively connected to thesource of motive power to obtain driving power therefrom and having thesecondary tether wound thereon for paying out and reeling in thesecondary tether in accordance with the movements of the submarinevehicle.

5. A tethered vehicle system according to claim 1 wherein the source ofmotive power includes a source of hydraulic power.

6. A tethered vehicle system according to claim 1 including an auxiliarydevice releasably mounted on the submarine vehicle for selective releasetherefrom to cooperate with investigated submerged objects.

7. A tethered vehicle system according to claim 1 further including amanipulator arm mounted on the submarine vehicle and effectivelyconnected to the source of motive power via the secondary tether forcontacting and performing work on objects within the vicinity of thesubmarine vehicle.

8. A tethered vehicle system according to claim 7 further including atool carried by the manipulator arm.

9. A tethered vehicle system according to claim 8 further including atelevision camera mounted on the submarine vehicle and connected via theaforesaid primary and secondary tethers to the support vehicle toprovide personnel therein a view of areas adjacent the submarinevehicle.

10. A tethered vehicle system according to claim 9 further including alight source mounted on the submarine vehicle for illumination ofobjects within the field of view of the television camera.

1. An undersea tethered vehicle system comprising: a support vehicle; aprimary tether connected to said support vehicle and extendingdownwardly therefrom for conducting electrical currents and supportingtensional forces therealong; a lift module attached to the primarytether for support thereby; a submarine vehicle configured for retentionwithin the lift module; a source of motive power housed within the liftmodule; and a secondary tether connected between the submarine vehicleand the lift module and effectively connected to said source of motivepower within the lift module for transmission of the motive powertherealong and effectively connected to the primary tether fortransmission of electrical currents therealong to permit the submarinevehicle''s movement into and out of the lift module and within apredetermined range thereabout.
 2. A tethered vehicle system accordingto claim 1 wherein the support vehicle is an aircraft.
 3. A tetheredvehicle system according to claim 1 wherein the lift module is enclosedon one end to minimize hydrodynamic interaction between the retainedsubmarine vehicle and the water during launch and recovery of thesystem.
 4. A tEthered vehicle system according to claim 1 furtherincluding a winch housed within the lift module and effectivelyconnected to the source of motive power to obtain driving powertherefrom and having the secondary tether wound thereon for paying outand reeling in the secondary tether in accordance with the movements ofthe submarine vehicle.
 5. A tethered vehicle system according to claim 1wherein the source of motive power includes a source of hydraulic power.6. A tethered vehicle system according to claim 1 including an auxiliarydevice releasably mounted on the submarine vehicle for selective releasetherefrom to cooperate with investigated submerged objects.
 7. Atethered vehicle system according to claim 1 further including amanipulator arm mounted on the submarine vehicle and effectivelyconnected to the source of motive power via the secondary tether forcontacting and performing work on objects within the vicinity of thesubmarine vehicle.
 8. A tethered vehicle system according to claim 7further including a tool carried by the manipulator arm.
 9. A tetheredvehicle system according to claim 8 further including a televisioncamera mounted on the submarine vehicle and connected via the aforesaidprimary and secondary tethers to the support vehicle to providepersonnel therein a view of areas adjacent the submarine vehicle.
 10. Atethered vehicle system according to claim 9 further including a lightsource mounted on the submarine vehicle for illumination of objectswithin the field of view of the television camera.